How Panic Doomed an Airliner

On the evening of May 31, 2009, 216 passengers and 12 crew members boarded an Air France Airbus 330 at Antonio Carlos Jobim International Airport in Rio de Janeiro, Brazil. The flight, Air France 447, departed at 7.29pm local time for a scheduled 11-hour flight to Paris. It never arrived. At 7 o'clock the next morning, when the aircraft failed to appear on the radar screens of air traffic controllers in Europe, Air France began to worry, and contacted civil aviation authorities. By 11am, they concluded that their worst fears had been confirmed. AF447 had gone missing somewhere over the vast emptiness of the South Atlantic.

How, in the age of satellite navigation and instantaneous global communication, could a state-of-the art airliner simply vanish? It was a mystery that lasted for two years. Not until earlier this year, when autonomous submersibles located the airliner's black boxes under more than two miles of water, were the last pieces of the puzzle put together. What doomed the 228 men, women and children aboard Air France 447 was neither weather nor technological failure, but simple human error. Under pressure, human beings can lose their ability to think clearly and to properly execute their training-a well-known failing that has proven all too difficult to eliminate.

Over at Popular Mechanics I've got a long piece offering a detailed blow-by-blow account of how one of the co-pilots of the Air France jetliner managed, in the course of just five minutes, to take a perfectly operational airplane from an altitude of nearly seven miles down to impact with the ocean. Here, I'd like to offer a nutshell summary of what happened, and what our understanding implies for the future of air safety.

Air France 447 was operating with three pilots: a captain, who was the most senior crewmember, and two co-pilots. At any given time, two of them were required to be in the cockpit, seated at the pair of seats equipped with controls. Four hours into the flight, the captain went to take a nap, leaving the flying of the plane to the more junior of the co-pilots, Pierre-Cédric Bonin. Sitting beside him was the other co-pilot, David Robert.

The crisis began mere minutes later, when the plane flew into clouds roiling up from a large tropical thunderstorm, and the moisture condensed and froze on the plane's external air-speed sensors. In response, the autopilot disengaged. For a few minutes, the pilots had no way of knowing how fast they were going, and had to fly the plane by hand-something, crucially, that Bonin had no experience doing at cruise altitude.

The proper thing for Bonin to have done would have been to keep the plane flying level, and to have Robert refer to a relevant checklist to sort out their airspeed problems. Instead, neither man consulted a checklist, and Bonin pulled back on the controls, causing the airplane to climb and lose airspeed. Soon, he had put the plane into an aerodynamic stall, which means that the wings had lost their ability to generate lift. Even with engines at full power, the Airbus began to plummet toward the ocean.

As the severity of their predicament became more and more apparent, the pilots were unable to reason through the cause of their situation. Despite numerous boldfaced clues to the nature of their problem-including a stall-warning alarm that blared 75 times--they were simply baffled. As Robert put it, after the captain had hurried back to the cockpit, "We've totally lost control of the plane. We don't understand at all... We've tried everything."

Psychologists who study performance under pressure are well aware of the phenomenon of "brain freeze," the inability of the human mind to engage in complex reasoning in the grip of intense fear. It appears that arousal of the amygdala causes a partial shutdown of the frontal cortex, so that it becomes possible to engage only in instinctive or well-learned behaviour.

In the case of Air France 447, it appears that Bonin, in his panic, completely forgot one of the most basic tenets of flight training: when at risk of a stall, never pull back on the controls. Instead, he held back the controls, in a kind of panicked death-grip, all the way down to the ocean. Ironically, if he had simply taken his hands away, the plane would have regained speed and started flying again.

Compounding the problem was a peculiar feature of the Airbus's cockpit layout. Unlike a Boeing jet, in which one pilot's movement of the control yoke moves the other pilot's yoke as well, an Airbus features "asynchronous" controls, meaning that moving one control doesn't cause the other to move as well. Bonin's colleagues probably never knew that he had the controls all the way back-perhaps because they never imagined that any certified airline pilot could engage in such a misguided response.

Perhaps the most tragic moment of the entire transcript occurs in the final moments, when Bonin at last tells the others that he has had the controls back the entire time. "No, no, no," says the captain. But by then it is already too late.

What can we learn from AF447? Above all, the tragedy reinforces an unfortunate truth about air travel that many passengers do not appreciate: that the most dangerous component of a modern commercial jetliner is the brain of the pilot at its controls. The majority of fatal airline accidents (vanishingly rare though they may be) are due to pilot error.

One way that airline manufacturers have tried to work around this problem is to increase the amount of automation, so that planes can largely fly themselves. But this tendency has had an ironic effect: the more pilots rely on automation, the less practiced they are at flying a plane by hand when an emergency requires it.

As a pilot myself, I love taking the controls of an airplane and through it finding a perfect freedom of movement in the sky. I would never want a computer to take that away from me. But the practical reality of moving passengers in perfect safety from point A to point B requires a different perspective. As technology improves, and flight control systems become more sophisticated, the relative inadequacy of we two-legged mammals will only become more apparent. Ultimately, the idea of a relying on a human being in the cockpit may come to seem a sentimentality too expensive to afford.

Auto drivers regularly do similar things on ice (e.g. keeping a wheel turned or the brake depressed, thereby losing all control). A common mistake of drivers who step on the wrong pedal (unaware that they did) is to press it all the harder. As cars become more automated (auto-braking features no longer are rare), we'll have to see if driver's skills decline further, too.

The aviation disaster in Michael Crichton's bestseller "Airframe" happens in a very similar way: while the veteran, senior pilot went for coffee, he let his son, a relative novice pilot, fly the plane. When a minor problem occurred, the young pilot COULD have solved the problem just by letting go of the controls! Instead, by holding on, he created a "dolphing" effect (the plane going up and down and up and down, like a dolphins leaping throug hthe ocean) that killed a number of passengers.

Mr.Wise, your name is an oxymoron, since the kind of discussion you offer up regarding the AF 447 is as scientific and enlightening as the pseudo science you practice. As a Boeing pilot with more than 15 years experience flying heavy jets all over the world your comments only help the misunderstanding the public has about my profession. You attribute the loss of this airliner to the panic of 2 highly trained individuals operating at the limits of their physiological and professional abilities. Yet your analysis seeks to discredit their skill and judgment based on your arm chair observations going so far as to offer up the simple solution, that these pilots in the crucial moment forgot the simplest of all flying skills, how to recover a stall. You go further by saying these poor men could have benefited from hand flying skills you have flying a Cessna. You prove your ignorance by implying Airbus aircraft are less safe because unlike Boeibg airliners they offer their pilots only limited feedback on control inputs. For your information modern Boeing airliners like the ,777 and 787 do not give pilots any greater safety advantage over airbus pilots since in both Airbus and Boeing aircraft are fly by wire, and the feedback generated by the controls of all these aircraft are both artificial. In complete darkness in instrument flying conditions and in turbulence, as was this situation, is not the place to trust seat of your pants flying you seem to think would have saved these unfortunate people. The pilots where looking at their instrumnents and it was this observation that betrayed them, the circumstances surrounding this are not clear that clearly the instruments were at some point entirely unreliable. If you want to discuss this accident why don't you try instead working from the facts Mr.Wise and look at the massive operational pressures placed on these men to operate an airliner through the area they passed that night, and why at the crucial moment their instruments and aircraft failed to provide them with the necessary safeguards to avert this tragedy. Panic didn't kill anyone the day AF447 crashed, and to imply this clearly shows you know nothing of what you are talking about.